Added javadoc comment for postQuestion and postSolution.
Merge branch 'master' of github.com:huskysoft/403Interviewer
Checks parameter in postQuestion and postSolution. Changed the exception thrown to IllegalArgumentException.
Checks parameters in NetworkService.java.
Check question and solution has nonempty text/title.
Populate question and solution object with authorId and dateCreated.
Check nonnull category and difficulty.
Merge pull request #101 from kevinloh/master

Javadoc comments for postQuestion and postSolution.